bzoj3698

显然是有源有汇有下界最大流，不刷不知道，一刷吓一跳
发现了我之前求有源有汇有下界最大流的错误，具体见我那篇介绍有下界的网络流的解题报告(bzoj2502)，已经更正

 const inf=;
 type node=record
        po,next,flow:longint;
      end;

 var e:array[..] of node;
     pre,p,numh,h,cur,d:array[..] of longint;
     a:array[..,..] of double;
     len,tot,i,j,n,s,t,ss,tt:longint;

 function min(a,b:longint):longint;
   begin
     if a>b then exit(b) else exit(a);
   end;

 procedure add(x,y,f:longint);
   begin
     inc(len);
     e[len].po:=y;
     e[len].flow:=f;
     e[len].next:=p[x];
     p[x]:=len;
   end;

 procedure build(x,y,f:longint);
   begin
     add(x,y,f);
     add(y,x,);
   end;

 function sap(s,t:longint):longint;
   var u,neck,tmp,i,j,q:longint;
   begin
     fillchar(numh,sizeof(numh),);
     fillchar(h,sizeof(h),);
     for i:= to tt do
       cur[i]:=p[i];
     u:=s;
     sap:=;
     numh[]:=tt+;
     neck:=inf;
     while h[s]<tt+ do
     begin
       d[u]:=neck;
       i:=cur[u];
       while i<>- do
       begin
         j:=e[i].po;
         if (e[i].flow>) and (h[u]=h[j]+) then
         begin
           neck:=min(neck,e[i].flow);
           cur[u]:=i;
           pre[j]:=u;
           u:=j;
           if u=t then
           begin
             sap:=sap+neck;
             while u<>s do
             begin
               u:=pre[u];
               j:=cur[u];
               dec(e[j].flow,neck);
               inc(e[j xor ].flow,neck);
             end;
             neck:=inf;
           end;
           break;
         end;
         i:=e[i].next;
       end;
       if i=- then
       begin
         dec(numh[h[u]]);
         if numh[h[u]]= then exit;
         q:=-;
         tmp:=tt;
         i:=p[u];
         while i<>- do
         begin
           j:=e[i].po;
           if e[i].flow> then
             if h[j]<tmp then
             begin
               q:=i;
               tmp:=h[j];
             end;
           i:=e[i].next;
         end;
         cur[u]:=q;
         h[u]:=tmp+;
         inc(numh[h[u]]);
         if u<>s then
         begin
           u:=pre[u];
           neck:=d[u];
         end;
       end;
     end;
   end;

 begin
   len:=-;
   fillchar(p,sizeof(p),);
   readln(n);
   dec(n);
   s:=; t:=*n+; ss:=*n+; tt:=*n+;
   for i:= to n+ do
     for j:= to n+ do
       read(a[i,j]);
   for i:= to n do
   begin
     if a[i,n+]<>trunc(a[i,n+]) then
       build(s,i,);
     d[i]:=d[i]+trunc(a[i,n+]);
     d[s]:=d[s]-trunc(a[i,n+]);
     if a[n+,i]<>trunc(a[n+,i]) then
       build(i+n,t,);
     d[i+n]:=d[i+n]-trunc(a[n+,i]);
     d[t]:=d[t]+trunc(a[n+,i]);
   end;
   for i:= to n do
     for j:= to n do
     begin
       if trunc(a[i,j])<>a[i,j] then build(i,j+n,);
       d[i]:=d[i]-trunc(a[i,j]);
       d[j+n]:=d[j+n]+trunc(a[i,j]);
     end;
   for i:=s to t do
     if d[i]> then
     begin
       build(ss,i,d[i]);
       tot:=tot+d[i];
     end
     else if d[i]< then build(i,tt,-d[i]);
   build(t,s,inf);
   if sap(ss,tt)<>tot then writeln('No')
   else writeln(sap(s,t)*);
 end.